1. Field of the Invention
This invention relates to an electromagnetic signal processing system and more specifically, but not exclusively, to a system of processing an optical signal.
2. Discussion of Prior Art
WO02/29436 teaches that a laser-radar receiver should comprise an array of optical fibres which are connected to at least one radiation detector, each optical fibre having different physical characteristics which result in known delays in the transmission time of pulsed electromagnetic radiation. Such delays are conveniently achieved by using optical fibres of differing lengths so that they operate as delay lines. Arrays of 3×3 optical fibres are taught, each optical fibre connected to single avalanche photo-diode (APD).
In our co-pending UK patent application number 0322564.6, we have taught that an electromagnetic signal processing system may comprise a plurality of optical fibre arrays, each optical fibre array having a cluster of optical fibres with their one ends oriented to receive electromagnetic radiation and arrange to transmit electromagnetic radiation to an array output, the array outputs being connected to transmit electromagnetic radiation in sequence to a signal detector input. In this co-pending application we have also taught various additional features for such signal processing systems.